Traditionally, techniques for measuring the flight parameters (launch parameters) of the ball, such as a golf ball exist a lot. For example, Patent Literature 1 discloses a method of measuring launch parameters of an object in flight. The method comprises capturing a plurality of images of an object in flight, identifying a radius of the object and a center of the object in each of the plurality of images, and calculating a velocity, an elevation angle, and an azimuth angle based on the radius of the object, the center of the object, and pre-measured camera alignment values. Further, the method comprises cropping the plurality of images to a smallest square that bounds the object, flattening the plurality of images from spherical representations to Cartesian representations, converting the Cartesian representations to polar coordinates with a range of candidate centers of rotation, and based on a fit of the polar image pair, measuring the spin axis and spin rate.
Patent Literature 2 discloses a method for determining parameters of an object in motion. The method comprises the steps of calibrating a camera lens to establish (x, y, z) directions for every (x, y) pixel in an image plane of the camera, determining alignment correction factors, capturing a plurality of images of the object in motion, finding the object in each of the plurality of images, calculating three dimensional coordinates for each of the plurality of images, and calculating a velocity vector for the object from the three dimensional coordinates. Further, the method comprises the steps of rotating a reference image of the plurality of images by a first set of rotations of a plurality of rotation sets, scaling the rotated reference image to a target image, correlating the reference image to the target image to obtain an incremental score of a plurality of scores, repeating the steps of rotating, scaling and correlating in a stepwise refinement manner to obtain a best score of the plurality of scores and utilizing a best rotation set of the plurality of rotation sets to determine the parameters of the object in motion.